For many years Internet Explorer was the top dog when it came to web browsers. That was back when IE was the bundled browser with Windows and a lot of people didn’t know there were alternatives. Today, however, IE is under attack from more nimble competitors.

Back in November, Google Chrome put IE into second place in terms of usage according to StatCounter. The latest numbers show that IE is again slipping against Chrome and other browsers. The details on browser usage come from Net Applications and they show that over 2011 IE dropped seven points against the competition. At the end of December, IE was down to 51.9% of the browser market.

Google Chrome took that entire share that IE gave up and grew 9/10ths of a point during the same month to get 19.1% of the market. Net Applications believes that IE will slip below 50% of the market as early as March of 2012. Microsoft is still choosing to focus on how well IE works on Windows 7.

"Based on where the December data currently stands," said Roger Capriotti, the head of IE marketing, in a Dec. 30 blog, "we're pleased to say IE9 ... will soon take the top spot from IE8 on Windows 7, with usage share expected to come in at nearly 25.6% this month."

Across all operating systems, IE9 had 11.5% share of the market in December and IE8 had 27.3% making it the most popular version. The numbers from Net Applications show that Firefox will slip to third behind Chrome by March.